This invention relates to furnaces. In one of its more specific aspects, this invention relates to a means for, and a method of, reducing refractory wear and spalling within a glass furnace and, more particularly, in glass furnace throats.
The use of refractory-lined furnaces to melt glass batch to produce melted glass from which glass fibers are formed is well known. In some types of furnaces, the melted glass is passed from the melting portion of the furnace through one or more channels having a throat, all of which construction is refractory lined. Because of the velocity and temperature of the glass through such a throat, considerable wear, or spalling, of the refractory can take place. This results in two disadvantages; first, the furnace life can be shortened with the result that considerable downtime for repairs is required and, secondly, some portion of the refractory becomes included in the glass as small particles which act to diminish the efficiency of downstream portions of the equipment. For example, when the melted glass containing such particles is introduced into bushings from which glass fibers are pulled, these particles can plug the apertures of the bushing, thus decreasing the amount of glass fibers which can be continuously drawn through the bushing.
Such refractory wear is generally concentrated at exits from narrow passages or at sharp angular changes in the direction of the glass flow in the channels leading from the furnace and the high temperatures existing at such points contribute significantly to that wear.